CRA personal filing -interest accruing before the due date
So what happened is this:
I filed personal taxes on April 20th and I got my Notice of Assessment ready to view online on May 1st.
On the Notice of Assessment I owe the CRA lots of money and it say payment is due by May 21st. Fine with me.
I log in this week and I see that interest is already piling up and compounded daily.
I google and apparently I had to pay by April 30 or interests will be accrued.
I realize i done goof here, but why is the process so misleading?
I couldn't see my NOA until May 1st (1 day after my balance was due) and why would the NOA have a pay by date if it doesn't mean anything?